feat: add proxy template origin field and implement socket utilities for log streaming

backend/app/models/template.py

@@ -19,8 +19,14 @@ class ProxyTemplateDocument(BaseModel):
     code: str = Field(..., description="Addon source code")
     source_url: str | None = Field(default=None, description="Reference URL")
     built_in: bool = Field(default=False, description="Provided by thePlug")
+    origin: str = Field(default="custom", description="Template source")
     created_at: datetime | None = None
     updated_at: datetime | None = None
+    source_path: str | None = Field(
+        default=None,
+        description="Filesystem source path",
+        exclude=True,
+    )
 
 
 class ProxyTemplateCreateInput(BaseModel):